Abstract

MgO magnetic tunnel junctions with and tunnel magnetic were patterned into pillars with different geometries with areas up to . Sensors were incorporated in thick flux guides with different shapes and free layer stabilization was achieved through internal ( pads) and external longitudinal bias fields . Sensitivities of were obtained in the center of the transfer curve. Noise levels of at , at , and at were measured in the linear region of the transfer curve.

Received 12 September 2007Accepted 07 December 2007Published online 14 March 2008

Acknowledgments:

This work has been partially supported by POCTI∕CTM∕59411∕2004 and EC FP6-NMP4-CT-2005-017210 (Biomagsens) Projects. One of the authors (R.C.C.) wishes to thank FCT for his Ph.D. grant (SFRH∕BD∕32562∕2006). INESC MN acknowledges FCT funding through the Associated Lab-Instituto de Nanotecnologias.